Like I stated earlier, I have cut at 3/16" with one pass with a 1/8" bit. I have done this many times for making edge lit projects. A trick that I picked up on was that you can flame polish cast acrylic. Propane will not give enough heat with out extra help, but Mapp gas burns hotter and does have the heat to get the job done. Sand, then polish, then to get that clear edge we want to see again, heat brings it out for you quick and easy.